In a small bowl, mix mayonnaise, dashi powder and mentsuyu to make the mayo dressing.
In a large bowl, mix cabbage, green onion, corn and crumbled french onion. Gradually add the mayo dressing and stir to desired consistency.
Chill at at least 30 minutes before serving.
Meanwhile, cook bacon in a large skillet over medium-high heat until browned. Drain the bacon, crumble and set aside.
Before serving, top with bacon, benishouga (red ginger) and any additional toppings as desired. Drizzle Tonkatsu sauce. Mix then serve immediately.